1. Field
Example embodiments relate to a light-emitting device and a light-receiving device using a transistor structure, and more particularly, to a light-emitting device and a light-receiving device using a transistor structure, in which a light-emitting layer, an electron-transporting layer, and a hole-transporting layer are provided between the source electrode and the drain electrode of a transistor in a direction parallel to these electrodes, thereby increasing the lifespan of the device, facilitating the manufacturing process thereof, and realizing light-emitting and light-receiving properties having high efficiency and high purity.
2. Description of the Related Art
In general, an electroluminescent device is a device using a phenomenon by which light is emitted when an electric field is applied to a predetermined material, in which electrons and holes are injected to a light-emitting layer, form excitons and are then recombined, thus emitting light. For the driving of the device, the driving of a transistor is mainly employed in order to decrease the size of the device and increase the efficiency thereof.
However, because the light-emitting portion of the device and the portion of the transistor that drives it are formed independently of each other, there are problems in that the overall size of the device is increased and the manufacturing process thereof is not easy. In recent years, research towards a light-emitting device in which the light-emitting portion and the driving portion are integrated with each other has been conducted.
US Publication No. 2005-0247924 discloses a light-emitting device using continuously charged nanocrystals, in particular, a light-emitting device having a transistor structure, which includes a substrate, a source, a drain, a channel portion, gate oxide, and a gate electrode. When the above light-emitting device, including one or more Si nanocrystals in the gate oxide, is subjected to alternating-current (AC) driving, electrons and holes, which are injected from the gate electrode, meet together and form excitons, consequently emitting light. Although this device has a structure in which the light-emitting portion and the transistor, as the driving portion are integrated with each other, it has neither a hole-transporting layer nor an electron-transporting layer, undesirably making it difficult to effectively inject the holes and electrons. Furthermore, it is impossible to selectively set the light-emitting region through the control of the magnitude of the electric field that is applied to the gate electrode, undesirably decreasing the lifespan of the device.